Weft detector system for shifting box ends of looms



s. vosE 2,054,185 WEFT DETECTOR SYSTEM FOR S HIFTING BOX ENDS OF LOOMS Original Ffiled May 7, 1955 2 Sheets-Sheet 1 as 37 Att or neqs Shuttle Changer Sa\eno i d a 0 T" w l. 6 01m 7.! i m s w RI 5 Bl \n 1%. W 4 H l G Q m 3, I 1 m f a m n T 0. K q.

Sept. 15, 1936.

Pattern Mechx L. s vos; 2,054,185 WEFT DETECTOR SYSTEM FOR SHIFTING BOX ENDS OF LOOMS Sept. 15, 1936.

Original Filed Ma '7, 1955 2 Sheets$heet 2 Inventor Lewis S. Vase W Attorneys 7 Patented Sept. 15, 1936 ,UNITED STATES PATENT OFFICE Crompton & Knowles Loom Works, 'Worcester, Mass, a corporation of Massachusetts Application May 7, 193-5, Serial No. 20,117 Renewed August 4, 1936 12 Claims.

This invention relates to improvements in weft detecting systems for fancy or multi-shuttle looms and it is the general object of the invention to provide such a system usable more .particularly 6- on the shifting shuttle box end of the loom and eifective to detect the shuttle immediately before it is picked whether previously active or inactive.

Looms of'the type to which my invention more particularly relates ordinarily employ shifting shuttle boxes on at least one end of the lay, the boxes shifting while the lay is in the forward part of its sweep to render a previously inactive shuttle active. The shuttle boxes can remain at rest for an extended period during which either of the shuttles remains in action. In my co-pending' application Serial No. 593,814 I have shown a pair of electric weft detectors secured to the lay, one over and the other under the boxes, so related to the latter as to have detecting relation with the an inactive shuttle but incapable of detecting the active shuttle. In such a loom the period during which any one shuttle may remain active is necessarily limited. It is an important object of my presentinvention to add a third or auxiliary de '25 tectcr positioned and controlled to detect in the active shuttle only, thereby supplementing the other two detectors and permitting any one shut tie to remain in action as long as desired. The third detector may, conveniently be mounted in front of the lay to detect the active shuttle on those forward beats of the lay when there is no shifting of the boxes. When there is to be a change in the running or weaving shuttle the boxes will shift during the time that the additional detector would ordinarily feel for the con-- dition of weft and it is a further object of my in vention to provide means for moving the addi tional detector out of interfering position with re* spect to the boxes when they shift.

The detectors secured to the lay will ordinarily operate to indicate exhaustion when a depleted shuttle previously inactive is about to be returned to action by shifting of the boxes and I provide a control originating in the pattern mechanism for permitting one or the other of these detectors to communicate indication of weft exhaustion to a means for changing loom operation during those picks when the additional detector is removed from detecting position. In this way I provide 'for detecting the condition "of weft in each shuttle before 14; is picked irrespective of whether it was previously active or inactive. The control for the detectors may includes. switch movable by the pattern mechanism "or in some other way coordihated: the shifting boxes 'sothat the detector of the inactive shuttle will be incapable of indicating exhaustion when the third detector is positioned for a detecting operation.

Any one of a variety of mechanical devices may be employed to move the additional detector to non-detecting position, but I have shown a cam surface and actuator therefor brought into action by apart which moves in timed relation with the shifting boxes. I do not wish, however, to be limited to a cam inasmuch as this is not the only means by which the additional detector can be moved out of detecting position at the desired times.

With these and other objects in view which will appear as the description proceeds, my invention resides in the'combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings, wherein a convenient embodiment of 'my invention is set forth,

, Fig. l is an end elevation of the shifting box end of the loom having my invention applied thereto, certain parts being in section,

Fig; 2 is a front elevation on an enlarged scale partly in section taken in the direction of arrow 2,-Fig. 1, Fig. 3 is a front-elevation taken in the direction of arrow 3-, Fig. 1, showing the control for the box motion and switch, certain of the structure being in section,

Fig. 4 is a view similar to a portion of Fig. l with the additional detector moved out of the path of the shifting boxes and indicating diagrammati cally the path traversed by the shuttles and their bobbins during shifting,

Fig. 5 is a diagrammatic view of the electric circuits indicating the form of control adaptable to a continuously running shuttle changer "of a type which has gone into general use, 7

Fig. 6 is a fragmentary diagrammatic view indi--' cating control means for another type of shuttle changer of well-known construction, and Fig. 7 is a modification showing a different means for mounting the additional detector.

Referring to Figs. 1 and 2, I have provided a looin frame 10 having a lay I l movable back andforth relatively to the front of the loom bya conmotor 12 driven by the top shaft 13. A lay end M has slidably mounted thereon a gang of boxes .13 comprising upper and lower cellsl5 and t6, respectively, mounted on a box lifter rod H. The lower end-of the rod is connected to a yielding link I 8 attached as at I 9 to a box lifter lever 20. The latter may be pivoted to a fixed stud 2| and ex.- tends rearwardly to be connected to a depending link 22. The" lower end of the latter is pivoted to a disk 23, see Fig. 3, secured to a short shaft 24 driven intermittently by a pinion 25.

The latter has two separated segments of gear teeth and is provided with two bull teeth 26 and 21, respectively, which are displaced with respect to each other along the length of the shaft 24 so that only one tooth at a time can cooperate with a segmental master gear 28-secured to the bottom shaft 29. V V V The bull teeth are moved; by, a sliding positioner 33 having a stem 3 iwhich extends through a box motion frame 32 secured to the loom. The

I stem is surrounded by a compression spring 33 which tends normally to' move the positioner to the left asviewed in Fig. 3, while a'fiexibleconnector 34 attached to the positioner as at 35.extends around a fixed sheave 36 and upwardly to be attachedas at 31 to a pattern lever 38..

Lever 38 is movable either to high or low posi "tion by' a pattern chain 39 consisting ofhigh and l'ow'rolls fl and flfl, respectively. The chain can be built toprojduce any desired pattern'having two-different colored wefts, 'that'is, the pattern may have a series of successive high or low" rolls as indicatedin the lower portion of the 'chain'shown in Fig.3; orthe highand low rolls may alternate as shown in-the upper part of the chain immediately under the pattern le ver .38.

The pattern lever moves about a fixed pivot 42 and'when rising moves the position'er 30 to the right as viewed inFigLZE. but when falling per mits the spring 33 to move the positioner to the left; V 7 'Bo-x motions of the'typeindicated are well-' known'and a further description is deemed unnecessary; It issufficient for present purposes to :state that rising of the pattern lever'38 is ac- V companied'by anlupward shifting of the shuttle 45. '7 ball of the pattern chain corresponds to two sucboxes by 'a force-originating in the master gear 28 and transmitted through'the link 22, lever 20, and box lifter rod. I1. The bottom shaft has a complete revolution every second beat of the loom andth'espattern' chain is given arr advance movement also on every 'second beat, so that one ""c'essiv'e" beats of the loom. 'The matter thus far described may be as commonly used in box looms.

' end It andjhaving mounted thereon an electric LJAs shown more particularly in Fig. 2 I provide a bracket 4.0 extendingupwardly from the lay detector M'from which extends two electric con-' ducting' wires 42 and 43.

' spect to-theupper' cell I5 when the ftive and the boxes are'down.

The detector is providedwith a pair of detecting fingers or prongs 44 which are adapted for engagement with the 'bobbin's -W of the'shuttle Sin the-upper box, and

contacts with a conducting surface such as a metallic ferrule in the shuttle when the weftis substantially depleted. Detector II is posi-' tioned tobe out of detecting relation-with relatter is.ac-

--In a similar manner Iprovrde a second bracket .50 depending from thelay end and carrying a second electric detector l from which extend conducting wires 52' and 53. respectively, De tector fingers or prongs 54 extend upwardly from the detector to detect bobbin W'in shuttle S in the lower cell 5 in a manner similar'to that already described in'connection with-the upper i detector Al. and 'detect their 7 corresponding shuttles "only whenthe latter are inactive.

l The-two feelers of the detector mechanism secured to the lay have detecting relation with their corresponding shuttles due 'to shifting of about a fixed axis 13.

the shuttle boxes. The detectors may if desired be similar to those shown in Payne Patent No. 1,924,197.

. The detectors 4| and 5| and the manner in which they cooperate with shuttles S and S of themselves form no part of my present invention, being similar 'to the corresponding parts 'shown in my co -pending application Serial No. 593,814.

As previously stated the detectors 4! and 5| operate-in such a manner as to restrict the loom to ,theweaving of very simple patterns, such for instance, as two picks of one character of weft. followed by two picks of a different character of,

weft. In order to render the loom capable of I- provide an additional detector mechanism to cooperate with the active shuttle which normally cannot be detected by the detectors mounted on the lay.

weaving with any desired sequence'of wefts of .two different characters as in call box weaving Accordingly,'as shown in thepreferred formof Q connected by an uncovered conducting surface in As shownin Fig.1 the detec V the active shuttle. V tor is mounted on a slide 65 movable backwardly and forwardly in a stand 66 secured to the loom frame. -A light tension spring 61 interposed between a part of -the stand 66 and a depending finger. 68 of the slide tends to move'the detector 60' rearwardly into detecting position. A pin 69 carried by the slide moves in a vertical slot'lO formed in the upper arm I I of a lever 12 'movable 4o 7 The lower arm 14 of the a lever is provided with a cam -15 having upper e and lower cam faces 16 andx'll, respectively, which cooperatewith a pin; or stud or the like I8 carriedby the forward end of the-box lever. 20.

V In a modification shown in Fig. 7 the d'etector 80 is mounted directly on the arm 8| of a lever 82' f mounted and'otherwise constructed similarly to lever 12. attendant parts are eliminated and a spring 83 In'the modification .the .slide 65 and holds thelever 82 yieldingly'in position to present 7 the detector 80 to the active shuttle. 1 0

In the operation of the structure thus fardescribed the boxes will have periods during which they are at rest with respect tothe lay' and other periods when they shift relatively'to the lay when the latter is in its forward position. Asshown in Fig. 2 the boxes are assumed to be down and at rest relatively to the lay. so that the'shuttleS is active. Under these conditions the forward part of lever 20 willalso'be downto place the stud 18 at the bottom of cam .face-TLand when lever 20 rises to shift: the boxes, stud 18 will move upwardly along cam facel'lto cause a rearward movement in-the arm 14. and'acorespending forward movement of'arm llythereby moving'the slide '65 and the. detector 'Bflgforwardly; r 'Byreference to Fig.4 this operation will be understood totbegin when the lay is'about in' its mid-position when. movirig' forwardly. 'I'he. bobbins. W, W'.., together with theinrespective shuttles S and 'S' will startqt'o shift before the 7 boxes have reached a. position where they could interfere with and damage the prongs, 6;|,ofthe.

stationary detector and as the-lay moves forwardly toward the detector the cam and pin 18 will cooperateto cause forward movement of the detector. The cam can be designed to give the desired-movement to keep the detector well in advance of the boxes so that as the latter shift relatively to thelay there is no opportunity for damaging the auxiliary detector.

When the lay reaches its extreme forward position the boxes are approximately half shifted at which time the stud 18 is on the high point 79 of the cam between the surfaces '16 and 11, after which continued running of the loom moves the lay rearwardly and the boxes recede fromthe detector as the stud 18 moves downwardly along upper cam face 76. The detector 60 and the lay therefore move rearwardly togethenand at the end of the box shift the detector is back in its normal detecting position. In this way the auxiliary detector is. moved out of detecting. position on the forward beat of the loom when a box shift occurred, and is therefore incapable-of giving indication of weft exhaustion and is also moved out of interfering position relatively. to the shifting boxes.

In Fig. 4 the boxes are shown at an intermediate position in their up shift, and the dot and dash lines a and b show the forward and upward paths traversed by the bobbins W and W respectively during such a shift.v The rear position'of the detector 66 is indicated in dotted lines corresponding to the dotted bobbins W and W, while the detector is shown as having moved forwardly to the full line position when the boxes and lay .reach front center position.

The shifting of the boxes already mentioned renders active a shuttle which was previously inactive and. this shuttle should have the weft thereof detected before it is picked to the opposite side of the loom. I make provision for this detection by the circuits indicated diagrammatically in Fig. 5. As shown therein the boxes are illustrated in their low position corresponding to Fig. 1 so that detector 5| can contact with a bobbin W in the lower shuttle S. A switch 90 has a pair of upper electrodes 9! and 92,, respectively, and an additional pair of lower electrodes 93 and 94, respectively. A contactor 95 is arranged to connect the members of each pair, one pair at a time, so that only one pair can be electrically connected, dependingyupon which shuttle is active.

The contactor is mounted on the lower end of an upwardly extending rod 96 connected to the pattern lever 38 at the pivot 31 thereof. It is to be understood that before a shift of the shuttle boxes canoccuran indication for the shift must be-given .by the pattern mechanism so that the lever 38, in order to effect the rising shift already described, must move upwardly prior to shifting 'of the boxes and while detector 5! is still capable of-giying-an indication of weft exhaustion in the lower inactive shuttle S.

i, By referring to Fig. 5 it will be seen that when the top shuttle Sis activethedetector 4! therefortemporarily out of detecting relation with this shuttle is'nconnected by wire 42 to electrode 93 and the'latter is connected by the contactor 95 to the electrode 94-. When the patternlever 31 rises preparatory to a box shift, however, the contactoriSlfi will rise to the dotted line .position shown in-Fig. 5,;thus connecting the electrodes 9| and 92:,whereupon, if exhaustion be present in the inactive shuttle, S, current will flow from the ground over wire 53, detector 5|, wire 52, electrode 9|, raised contactor 95, electrode '92, wire l'00,solenoid I01, wire l02,'source of electric power. P, and wire 103 back tothe ground. This circuit will be maintained from the time that lever 38 is raised until the boxes have risen far-enough to move the prongsor detector fingers of the lower feeler away from the weft surface W, but

during this closure, which is sufficiently long :for the purpose, energization of the solenoid H'H will move dog- I04 to the. left under a lever 105. .By means of mechanism not shown herein but employed in a well-known continuously running shuttle changing loom movement of the dog I04 as described will effect exchange of shuttles when shuttle S reaches the opposite Side of the loom. If the boxes had been raised so that cell 16 was in active position just prior to the shift, then it would be desirable to, detect into the upper box, and if depletion existed in thatbox the following circuit could be closed: ground, wire 43, detector 4|, wire 42, electrode 93, contactor 95 (which under the'assumed conditions would be down), electrode 94, wire H0, solenoid IBI, wire I,G2, so,urce of electric power P, and wire I93 back to the ground. This circuit is similar to the one previously traced and whenclosed will energize the solenoid to effect a change in loom operation. 7

If detector 69 indicates exhaustion of weft on non-box-shifting beats of the loom, the following circuit is closed: ground, wire 62, prongs or fingers 6|, wire 63, solenoid 19]., wire. I02, battery P, and wire I03 to ground. Excitation of the solenoid'result's in a'changelof loom operation as previously described. Magnet H5 could be energized in the same way. 1 r

Fig. 6 shows a type of loom control which can be employed with a loom which stops to effect shuttle change. Instead of the solenoid I0 II may employ a magnet orsolenoid I I5 mounted on the breast beam and operative to elevate a dog I16 into the path of a regularly reciprocating actuator I H, whereupon the latter will move the dog forwardly to rock a lever H8 and cause shipper handle H9 to move to stopping. position. A rod I20 is shifted longitudinally when the lever H8 moves to stopping position and thereby brings about shuttle changing operations during the period in which the loom is at rest, all of this well understood. a

From the description given in connection with Fig. 5 it will be seen that the detector of the inactive shuttle is rendered operative to com municate indication of weft exhaustion only on that beat of the loom when the inactive shuttle is to be returned to action by a shifting of the 7 boxes, and since it is at this time that the auxiliary or additional detector is rendered inoperative todetect, it will be seen that the detector system is capable of indicating exhaustion of weft in any shuttle which is about to be picked, whether that shuttle was previously activeuor inactive. j '1 From the foregoing it will be seen that I have provided a simple detecting system employing two detector mechanisms or the like one of which includes certain feelers which arerendered operative to indicate exhaustion of weft of an inactive shuttle about tobe returned to action, and the other of which provides an additional detector mechanism capable ofindicating weft exhaustion in the active shuttle only and during the period that such shuttle is to remain active. It will further be seen that the auxiliary detector is rendered inoperative to give an ind'ication of weft exhaustion from either shuttle when the boxes are shifting, so that thereis no opportunity for the detector mechanism on-the' lay to conflict'with the indicae tion given by the auxiliary detector. Also, the auxiliary detector is moved out of the'path of the shifting boxes to prevent breakage when the boxes are shifting and during that pick of the loom when one or the other of the feelers on the lay can indicate.

control of the feelers on the lay, the shifting of the boxes and the movement of the auxiliary feeler into and out of operative position are all exercised through the pattern mechanism, and that the lat-- 1 Having thus described my invention seen that changes and modifications maybe made 'thereinb'y those skilled in theart without departing from thespirit and-scope of the invention and I do not wish to be limited to the details herein,

ter can be so built as to provide any desired'sequence of. periods of shuttle activity. 7 V

it will be disclosed, but'what I claim is: I r

1.:In' a weft detector system efor a loom having a lay with two shifting shuttle boxes operating withtwo weavingshuttles, an electric weft detector'on the lay above the boxes to detect into the top box when inactive, a-second electric detector ion the lay below the boxes to detect into the lower box when inactive, pattern mechanism to determine which shuttle box is to be active, means to bring about .a changein loom operation, an electric switch controlled by the pattern mechanism to render the detector, corresponding to an inactive shuttle box about to become active capable of controllingthe means, a third weft detector to detect thaactive shuttle when the latter is'moved forwardly by the lay, connections between the third detector and the means to actuate the latter when exhaustion occurs in the active shuttle, and means ,7 to movethe third detector out of the' path 0 the boxes when the latter, shift. I ZJ-In a weft detector system for a loom having a lay with two shifting shuttle boxes operating with twofweaving shuttles, an electric weft detec tor. on the lay above the boxes to detect into the top boxwhen inactive, a second electric detector on the lay below the boxes to detect into the lower box when inactive, pattern mechanism to determine which shuttle box is to' be active, means to bring about a change in loomoperation, anelectric switch controlled by the pattern mechanism torender the detector correspondingto aninac- 'tive shuttle boxabout to become active capable of controlling the means, a third detector mounted'in 'front of theshuttle boxes and positioned to detect into the actively placed box, electrical connections between the third detector and the means to actuate'the latter when the third detec tor indicates exhaustion in an active box, and means to move the third detector out of detecting position when'the boxes shift with respect to the V lay. e

' 3. In a Weft detector system for a 100m having 'a lay with twoshifting shuttle boxes operating with two Weaving shuttles, an electric Weft detector en the lay above the boxes to detect into the top boxwhen inactive, a'second electric detector-on the lay below' the boxes .to detect into the "-lower box. when inactive, pattern mechanism to electric switch controlled by the'pattern mecha-' nism to render. the detector corresponding to an inactive shuttle box about to become active ca- :pable of controlling the means, a third electric detector mounted in front of the shuttle boxes determine which shuttle box is to be active, means to bring about a change in loom operation, an

Reference to ,Fig. 3 will show that the and positioned to detect into the actively. placed shuttle box, electric connections between the third detector and the means to actuate the latter when the third detectorindicates :exhaustion of weft in the active shuttle box, and means controlled bythe pattern mechanism to move the third de-" tector out of detecting position when the boxes shift. r

.4. i In a weft detector system. for a loom'having a lay with twolshifting shuttle boxes operating with'two weaving shuttles, an electric weft de-. tectoron'th'e lay above the boxes to. detectinto the top box when'inactive, a second electric. detectoron :the lay below the boxes todetect into 7 the lower 'box when inactive, pattern mechanism to determine which shuttle box is to be active,

means to bring about a change in loom operation;

an electric switch controlled by the pattern mech-,

anism to render the detectorcorresponding to an inactive shuttle boxabout to become active capable of controlling the means, a third detector to cooperate'with the activelyplaced shuttle box and control the means when exhaustion of weft occurs in the actively placed box, and means to move the third detector out of detecting position when the boxes shift.

5. Ina weft detectorsystem fora loom having 7 a lay with two shifting shuttle boxes operating with two weaving shuttles, an electric weft detector on the lay above the boxes to detect intothe top boxwhen inactive, asecond electric detector on the lay below the boxes to detectinto the lower box when inactive,- pattern mechanism to determine which shuttlew box is to be active, means to bring about a change in loom operation, an: elec-.' tric switch controlled by the pattern mechanism to render the detector corresponding to an inactive shuttle box about to become active capable of: controllingthe means, a' third detectorto cooperate with the actively placed shuttle box: and cone in the activelyplaced-box, and means -to move the third detector out of detecting position when the boxes shift, the last named means controlled by the pattern mechanism,-whereby the pattern mechanism rendersthe third detector inoperative when rendering either of the detectors carried by the lay capable of controlling the first named means. l I r 6. In a weft detecting system for aloom having a lay supporting two shuttle boxes to cooperate with two weaving shuttles, pattern mechanism to determine which shuttle boxshall be in active position, a pair of weft detectingmechanisms se cured to the lay, one for each shuttle box, to

tle, means controlledby the pattern mechanism to render operative the detecting mechanism cor-- responding to the inactive shuttle just prior to the return of said inactive shuttle to active position a third detector to detect the condition of weft in an actively placed shuttle box, and means controlled by the pattern mechanism to move the last named detector out of detecting position when the boxes shift, whereby each of the'weaving shuttlesis detected as to the condition of weft therein Within one beat of the loom of the time the shuttle is to become active, whetherthe'shut tle moves from inactive to active position or remains active.

'7. In a weft detectingsystem fora loom having a lay having two shuttle boxesoperating with positions, a pair of weft detectors secured tothe lay each to detect intoone of the 'shuttle boxes two shuttles each movable to active and inactive:

40 trol the means when exhaustion of Weft occurs r 55 detect the condition of weft in the inactive shut V 7 when inactive, pattern mechanism to render the detector corresponding to an inactive shuttle capable of controlling the loom just prior to the return of an inactive exhausted shuttle to active position, a third detector mounted in front of the shuttleboxes to detect into the actively placed box and effective when indicating exhaustion of weft in the active shuttle to control loom operation, and means controlled by the pattern mechanism to move the third detector out of the path of the shifting boxes when the latter shift relatively to the lay, whereby each shuttle is detected immediately before being picked whether previously active or inactive.

8. In a weft detecting system for a loom having a lay supporting two shuttle boxes operating with two shuttles each movable to active and inactive positions, pattern mechanism to determine which shuttle box shall be active, weft detecting means to detect the condition of weft in an inactive shuttle, means controlled by the pattern mechanism to render the detector mechanism operative to control the loo-m just prior to the return of the previously inactive depleted shuttle to action, additional weft detecting mechanism to detect the condition of weft in the active shuttle box and effective to control loom operation, and mechanism controlled by the pattern mechanism to move the additional weft detector out of the path of the boxes when the latter shift relatively to the lay, whereby each shuttle is detected within one heat of the loom from the time that it is to be active whether previously active. or inactive.

9. In a loom operating with two weaving shuttles and having shifting shuttle boxes movable relatively to a lay to render either shuttle active, pattern mechanism to determine which shuttle box shall be in active position, a weft detector secured to the lay in vertical alignment with the boxes to detect the condition of weft in one of the weaving shuttles due to shifting action of the boxes relatively to the lay when said shuttle is moved to inactive position, a second weft detector mounted in front of the boxes to detect the condition of an active shuttle, connections btween the pattern mechanism and said second weft detector to render the latter incapable of detecting weft when the shuttle boxes are shifting, and means to control the operation of the loom to be operatively related to both detectors and effective to change the operation of the loom when either detector indicates exhaustion of weft whereby the said one of the weaving shuttles is detected immediately before being picked whether previously active or inactive.

10. In a weft detecting system for a loom operating with shifting shuttle boxes to render either of two weaving shuttles alternately active and inactive, pattern mechanism to determine which shuttle box shall be in active position, a detector positioned to detect the condition of weft in one of the weaving shuttles when the latter is in inactive position due to shifting of the boxes, a

second weft detector adjacent the boxes to detect the condition of weft in either weaving shuttle when active, connections between the pattern mechanism and said second weft detector to render the latter incapable of detecting weft when the shuttle boxes are shifting, and loom controlling means to be operatively related to both detectors and capable of bringing about a change in loom operation when either detector indicates weft exhaustion whereby the said one of the weaving shuttles is detected immediately before being picked whether previously active or inactive.

11. In a weft detecting system for a loom operating with shifting shuttle boxes to render a weaving shuttle alternately active and inactive, a detector for the weaving shuttle when the latter has been rendered inactive by a shifting of the boxes, a second detector for the weaving shuttle when the latter remains in action due to nonshifting of the boxes, means to render said detectors alternately operative with respect to the weaving shuttle, said means rendering the first detector operative to detect the weaving shuttle when the latter becomes inactive and simultaneously rendering the second detector inoperative, said means rendering the first detector inoperative when the weaving shuttle returns to action, and means to bring about change in loom operation when either detector indicates exhaustion of weft.

12. In a weft detecting system for a loom operating with shifting shuttle boxes to render one or the other of two weaving shuttles either active or inactive, a lay to move the boxes backwardly and forwardly, weft detectors on the lay one over and the other under the boxes, each detector to cooperate with the corresponding shuttle box when the latter is inactive, a third weft detector mounted in front of the shuttle boxes to detect the condition of weft in the actively placed shuttle box, and means brought into action when the shuttle boxes shift relatively to the lay to move the third detector out of the path of the shifting 1 boxes.

LEWIS S. VOSE. 

